The Locked Mystery Box can be found while you are plowing land. If you receive the box then you will will get a pop-up notification stating for you to "Enter Passcode" or "Get Passcode". This feature is dependent on if you have signed up for FarmVille emails. You will not receive the Passcode (or the prize), until you sign up for FarmVille emails.
As said before, momentarily only a very small percentage of farmers will have access to this new feature. Eventually all farmers will have the opportunity to get this special Locked Mystery Box.
Now for the question that everyone wants to know, what's in the FarmVille Locked Mystery Box!?
::: Spoiler Alert :::
These are some confirmed Locked Mystery Box Prizes:
* Totem Pole
This article originally appeared on FarmVille Freak.